Lesson 13: toString(), toNumber()

[GaneshDonikena]

Hi everyone!,
My doubt is when to use
' toString()',
' toNumber()' in the scripts. Please help me. Thanks in advance!!.

 const amountDaiToBorrow = availableBorrowsETH.toString() * 0.95 * (1 / daiPrice.toNumber())

const amountDaiToBorrowWEI = ethers.utils.parseEther(amountDaiToBorrow.toString())

[krakxn]

The correct way to format inline code is using single backticks (not apostrophe) before and after the code, also: for discussions which need an answer should be set to the category "Q&A" from the menu on the right, as it helps others with similar doubts referencing the repo.

Simply:

toString() should primarily be used when printing stuff to the console. Whereas, toNumber() should be used for calculations.
Why? Because with toString() you can't really do mathematical operations with let's say, "1" + "5"; that would return "15", ie, concatenated. But with toNumber(), 1 + 5 would return 6.

Hope this helps!

[krakxn]

@alymurtazamemon This can be closed.

[GaneshDonikena]

Thanks a lot @krakxn

[SiegfriedBz]

Hello @krakxn
const amountDaiToBorrow = availableBorrowsETH.toString() * 0.95 * (1 / daiPrice.toNumber())
I don t understand as well why we use here to.string(), could you please explain ?

[krakxn]

Refer to my reply above :)

[SiegfriedBz]

I still don t get it.. @krakxn, can you please tell me if :
const amountDaiToBorrow = availableBorrowsETH.div(daiEthPrice).toNumber() * 0.95
is correct ?..

[krakxn]

@SiegfriedBz What is div() here?

Actually, create a new discussion (w/ the entire contract pasted) and tag me there to keep this thread organized; because uploading the context of the code here will be unnecessary.

[SiegfriedBz]

it s actually independant of the contract, it s about handling calculations in JS, toString(), toNumber(). I m confused with JS numeric imprecision on calculations
so I was wondering if it was "safer" for precision on calculations, to do :
availableBorrowsETH.div(daiEthPrice)
to make a division on 2 bignumbers
then .toNumber() to turn the result of this division in to a JS number, on which we can safely make a multiplication with a float number ?

[alymurtazamemon]

@GaneshDonikena @SiegfriedBz #2724 Give it a read and your doubts will clear

[SiegfriedBz]

Thank you @alymurtazamemon
I better understand why using toString() vs toNumber() : safe JS calculations on big-big (>2**53) vs not-so-big numbers
But still, since we are here in this file importing ethers.js, shouldn ' t we use it for handling all big numbers we manipulate ? I mean for consistency in the code
Thanks again for your help !

[alymurtazamemon]

@SiegfriedBz Yes you can use it and it will be even good to experiment with different things.

[SiegfriedBz]

Many thanks again @alymurtazamemon !